Light engine for and method of simulating a flame

ABSTRACT

An apparatus, system, and method for lighting effects, including simulating a flame. A three dimensional carrier includes an array of a plurality of light sources distributed on it. A control circuit coordinates on/off of the light sources in a manner to simulate a jumping flame. In one embodiment, the three dimensional carrier and LEDs are encapsulated in an at least partially light transmissive cover. This light modular engine includes a control circuit and an interface to electrical power. The system can include the light engine in a light fixture such as an architectural fixture. The methodology can include a sequence of on/off and brightness variations for the array of light sources.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to China patent application numbers201510152837.2 and 201520282857.7, both filed May 5, 2015, each of whichis incorporated by reference in its entirety herein.

I. BACKGROUND OF THE INVENTION

A. Field of the Invention

The present invention relates to lighting and, in particular, toapparatus, systems, and methods for producing lighting and lightingeffects that simulate the appearance of a flame or flames.

B. Problems in the Art

Artificial lighting continues to advance. The advent of solid-statelight sources such as LEDs has spurred further innovation.

The design of light sources for illumination purposes occupies asubstantial amount of the marketplace. Use of artificial light forparticular lighting effects is another major commercial area.

One particular area for lighting effects involves simulation of theappearance of flames. There has been a long-felt need for the same. Thiscomes from both safety concerns associated with real flames in suchthings as candle-based fixtures, gas lamps, or wood burning or gas flamefireplaces, as well as consumer-driven desire for the aesthetic andornamental appearance of flames.

One attempt at simulated candle flames uses an incandescentsingle-candle-flame-sized bulb with multiple filaments. A circuitswitches between the filaments to simulate a jumping candle flame.However, they have had limited success in the marketplace. It isdifficult to produce a realistic flame simulation. It is also difficultto expand the effect beyond the single bulb.

Bigger systems utilize such things as steady-state light sources butwith moving or rotating mirrors, reflectors, or lenses. They arerelatively complex. They involve the cost and complexity of moving partsand, again, have limited success in realistic simulation.

Attempts at using artificial light sources for log-fire flame simulationin such application as fireplaces also have limitations. Some areessentially or predominantly two-dimensional in the sense the simulationis in a vertical plane across a length and height in the fireplace. Thismight be deemed sufficient by some because most viewing-angles of afireplace are towards perpendicular to that plane. Such two-dimensionalsolutions lack realistic simulation, particularly for shallower viewingangles relative that vertical plane. Some use lights and mechanicaldevices. One example is a fan to blow illuminated red and/or yellow silkribbons vertically. The waving of the ribbons is intended to provide theflame simulation. This has limited three-dimensional effect and limitedrealism. It also creates noise and additional electrical powerconsumption over and above just lights. Some fireplace attempts utilizelight sources (incandescent or LED) to illuminate or edge-light a flatpanel or screen. The lights can be varied in intensity or color to tryto simulate flames at or in the panel or screen. This is atwo-dimensional solution which, again, works against realism in thesimulation. Some solutions play either a simulation or actual video offlames on a digital display. Again, this is two dimensional.

Some flame-effect lights use solid-state sources such as LEDs which havea smaller form factor and improved effective lives over sources likeincandescent sources. In some cases, they can also represent energysavings. Furthermore, driving them to different intensities that canchange quickly is possible. However, again, with regard to speciallighting effects such as flame simulation, the state-of-the-art hasconcentrates on 2D solutions or utilizing rotating optical devicesrelative the sources.

It can therefore be seen that a number of factors go into the design oflighting which attempts to simulate a flame or flames. Examples caninclude realism of simulation, cost of materials and components,operating costs, durability, and flexibility in how many forms they cantake and how many different applications they can be used. Some of thesefactors are antagonistic with one another, making it even more difficultto reach good solutions.

For example, the combination of lights and moving parts may helpsimulate the look of flames, but can add capital and operating costs. Itcan also create noise which can be antithetical to realistic simulationor to the consumer of such devices.

The repeating patterns of most simulated flames take two dimensionalforms, which allows viewers to know or perceive that they are looking ata simulated flame.

The inventor has therefore found there is room for improvement in thestate-of-the-art.

II. SUMMARY OF THE INVENTION

It is therefore a principle object, feature, aspect, or advantage of thepresent invention to provide an apparatus, a system, and method whichimproves over or solves problems and deficiencies in thestate-of-the-art. Further objects, features, aspects, and advantages ofthe invention include apparatus, systems, or methods which:

-   -   a. provide a more realistic flame simulation;    -   b. provide more of a 3D solution that provides a similar 3D and        even stereoscopic effect when viewed from multiple directions;    -   c. can be used in a wide variety of lighting applications;    -   d. is relatively economical regarding both capital and operating        costs over a typical effective life span;    -   e. provides the opportunity for a relatively long typical        effective life span;    -   f. can be implemented in a variety of form factors;    -   g. can include a stand-alone light engine module that can be        used in a variety of standard light fixture bulb electrical        sockets, or can be integrated or built-in to a fixture;    -   h. can be designed to create a variety of lighting effects;    -   i. can be essentially silent during operation;    -   j. is aesthetically pleasing;    -   k. is relatively noncomplex without moving mechanical parts;    -   l. generates a relatively small amount of heat;    -   m. has potential for long operating life;    -   n. can be made durable and robust for a variety of environments        of use including indoors, outdoors, and even underwater;    -   o. can be used alone or with surrounding optical surfaces or        fixtures, and can be used in combinations.

In one aspect of the invention, an apparatus according to the presentinvention comprises a light engine in a self-contained housing. Thelight engine includes a base with an electrical interface, an interiorthree-dimension form factor carrier, a plurality of solid-state lightsources distributed over at least a substantial portion of the carrier,a cover that at least substantially surrounds the carrier and lightsources and includes at least some light transmissive portions, and acontrol circuit for driving the light sources according to apredetermined regimen. In some embodiments the cover may be transparent.In some it may be translucent or partially light transmissive. In someembodiments there may not be a cover. The cover can enhance opticaleffects of a simulated flame. Furthermore, in some cases there can be acover over the LEDs (which could be transparent but might betranslucent) and then a second cover or shroud over the first cover andLEDs (which could be translucent but might not be). In this manner theLEDs could be protected by the first cover and then their light outputcould be manipulated by the second cover or shroud. In one example atranslucent second cover or shroud could diffuse the light output sothat individual LED output would not be seen, to promote the simulationof a flame.

In one example, the light engine has a universal threaded base that caninterface with standard electrical light bulb sockets. The housing isintegrated to enclose the light sources and light generated from thelight sources can issue in directions all around the housing. Theinterior carrier can be a flexible circuit board in a 3D shape. Atranslucent shroud covers the carrier and its light sources. The lightengine and housing can occupy at least substantially on the order of thesame space as mass-marketed light bulbs. However, it is to be understoodit can be scaled up or down according to need or desire. In anotherembodiment of the apparatus, the light engine can take a variety ofdifferent three-dimensional form factors. It may or may not have anouter cover. In some possible forms, just the set of light sources, andtheir control lighting sequence and timing, can be utilized. In manyembodiments, an outer cover can enhance the simulation of the appearanceof a flame. In one form the outer cover or shroud is translucent and inthe form of hammered or frosted glass.

The carrier presents a three-dimensional shape supporting a plurality oflight sources distributed at least around a substantial portion of it.The light sources have the capability of being driven individually or ingroups according to a certain preprogrammed regimen. The regimenactuates the light sources in a fashion that simulates jumping flamesfrom viewing angles all around the 3D shape.

A system according to the present invention includes a light engine suchas described above in combination with a light fixture. The lightfixture can include a variety of form factors, including differentarchitectural styles. A few non-limiting examples are lantern-style andpendant-light-style. The light engine can be placed inside the fixture.The fixture may or may not have light transmissive panes.

A method according to an aspect of the invention includes positioning aplurality of individual solid-state light sources in a three-dimensionalarray. Individual or groups of the LEDs sources are driven according toa predetermined regimen to simulate a leaping flame or flames byactuating LEDs according to a pre-programmed sequence.

Another aspect of the invention comprises simulating a flame effect withartificial lights by a particular repeating pattern of activation of athree-dimensional array of LEDs. The array has LEDs spaced apart fromeach other and populating most of the lower part of a three dimensionalshape. Small groups of LEDs are spaced from each other around the top ofthe array. Sets of LEDs are sequential activated at varying levels andtimes between bottom and top of the array, starting more at the bottomand moving or traveling to the top to simulate the leaping of flames.

In another aspect of the invention simulation of the flame effectinvolves a timing and sequencing of a three-dimensional array of LEDs orother individual light sources in a manner which is repeating but givesthe appearance of randomness. One way this can be done is by staggeringon-off sequences in different levels from top to bottom around thethree-dimensional shape but in a type of jumping up and down as itappears to rise and jump to the topmost portion. After looking at thebulb for several hours, the lighting pattern seems to be rotating aroundthe three dimensional surface. This gives the appearance of a randomnon-repeating pattern of the LEDs being turned on and off.

In another aspect more than one set of light sources in athree-dimensional configuration could be nested or distributed on thesame three-dimensional shape and have independent timing and sequencing.Such a plural combination could further enhance the appearance ofrandomness or nonrepeating flame effect for a more realistic effect. Inone embodiment this could simply involve plural sets of light sourceseach having its own dedicated timing circuit for on-off control butprogrammed to be different than the other sets in one or more ofposition, timing, or other parameters such as color of the light sourcesor output distribution patterns.

These and other objects, features, aspects and advantages of theinvention will become more apparent with reference to the accompanyingspecification and claims.

III. BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the U.S. Patent Office upon requestand payment of the necessary fee.

FIG. 1A is a perspective view of a light engine module according to oneexemplary embodiment of the invention.

FIG. 1B is a side elevation of FIG. 1A.

FIG. 1C is a top plan view of FIG. 1A.

FIG. 1D is a bottom plan view of FIG. 1A.

FIG. 2A is a side elevation of a light fixture according to oneexemplary embodiment of a system according to the present invention thatcould utilize the light engine of FIG. 1A and showing its connection tostandard household electricity diagrammatically.

FIG. 2B is a side elevation of an alternative embodiment of a lightfixture that could use the light engine of FIG. 1A.

FIG. 2C is another possible fixture embodiment that could use the lightengine of FIG. 1A.

FIG. 3 is a perspective view of a fixture similar to FIG. 2Aillustrating the illumination effect of a light engine such as FIG. 1Ainside it.

FIG. 4A is a side elevation and exploded view of the light engine ofFIG. 1A.

FIG. 4B is similar to FIG. 4A but from a 90° different perspective fromFIG. 4A.

FIG. 5 is a sectional view taken along 5-5 of FIG. 4A.

FIGS. 6A, B, and C are perspective, side elevation, and top plan views,respectively, of a cylindrical carrier (flexible circuit board formed ina cylinder) of an array of plural LEDs which can be placed inside thelight engine of FIG. 1A, shown in isolation.

FIGS. 6D and E are perspective and top plan views, respectively, of abottom end cap for the light engine of FIG. 1A, in isolation.

FIG. 6F is a perspective view of an electrical threaded base for thelight engine of FIG. 1A, in isolation.

FIG. 6G is a perspective view, in isolation, of an internal frame usedin the light engine of FIG. 1A.

FIG. 6H is a highly diagrammatic perspective view, in isolation, of atransformer for converting household line electrical voltage into alower voltage which can be mounted inside the light engine on the frameof FIG. 6G. A schematic of the circuitry inside the component, hardwires from the threaded base of FIG. 6F and to the circuit board of FIG.6I are shown in ghost lines.

FIG. 6I is a perspective view, in isolation, of a circuit board carryingcomponents of controlling the LEDs in the light engine of FIG. 1A.

FIGS. 7A, B, and C are reduced-in-scale perspective, front elevation,and top plan views of an outer translucent cylindrical cover, shroud,shade, or lens for the light engine of FIG. 1A, in isolation.

FIGS. 7D, E, F, and G are perspective, bottom plan, side elevation, andtop plan views of the top cover from the light engine of FIG. 1A, inisolation.

FIG. 8 is a block diagram of components of the circuit board of FIG. 6Ifor the light engine of FIG. 1A. Connection to the power transformer ofFIG. 6H is shown in ghost lines.

FIGS. 9A-D are electrical schematics of examples of the types ofcomponents of FIG. 8, including power filtering and voltage regulatingmodules (FIG. 9A), a DMX module (FIG. 9B), a control or CPU module (FIG.9C), and a driver module (FIG. 9D).

FIGS. 9E-G are optional features such as a speed control (FIG. 9E), aflame size control (FIG. 9F), and an infrared/body induction module(FIG. 9G) that could be used in the circuitry of FIGS. 6I and 8 andshown schematically.

FIG. 10 is an electrical schematic of one example of circuitry of anarray of plural LEDs such as could be used with the circuit componentsof FIGS. 9A-G.

FIG. 11 is an example of how an LED array circuit of the type of FIG. 10could be produced by printing conductive traces on a flexible circuitboard (here shown in plan view). The LED dies could then be surfacemounted to the printed traces, and the flexible circuit board withinstalled LEDs formed into the cylinder like shown in FIGS. 6A-C.

FIG. 12 is an illustration of and parameters of one example of LEDs thatcould be used in the LED array of FIG. 11 for the light engine of FIG.1A, including specifications for tricolor ratio, chromaticity, etc.

FIG. 13A is a diagrammatic illustration of one example of an LED arraylayout (in plan view) for a flexible printed circuit such as FIG. 11 forpurposes of describing lighting sequence of the LEDs to simulate a flameeffect using LEDs oft tricolor ratios and chromaticity selectionsillustrated in FIG. 12.

FIG. 13B is a timing diagram matched to the LED array of FIG. 13A. Asindicated it illustrates both level of driving of the LED (full on orpartially full on or off) as well as which of the LEDs at the numberedpositions in FIG. 13A are on at what time and in what sequence.

FIG. 13C is diagrammatic representations of the LED layout of FIG. 13Aat each sequence time 1-19 from FIG. 13B, showing at each moment in timewhich LEDs would be on or off and at what intensity.

FIG. 14 is a set of additional possible examples of lighting fixtures inwhich the light engine of FIG. 1A could be used, each shown insimplified side elevation.

FIG. 15 is a side elevation, partially exploded view of an alternativeembodiment of a light engine according to the present invention.

FIG. 16 is a side elevation view of a still further alternativeembodiment of a light engine according to the present invention.

FIGS. 17A and B are top plan assembled views and perspective explodedviews, respectively, for an alternative double-cylinder embodiment forLEDs and LED carriers, here plural such combinations, for a single lightengine according to another alternative embodiment of the presentinvention.

FIGS. 18A and B are top plan and perspective views of a still furtherstar-shaped alternative embodiment for a carrier and plural LEDsaccording to the invention.

FIG. 19 is a perspective view of another possible dome-shaped embodimentof the carrier and LEDs according to the present invention.

FIG. 20 is another potential alternative cone-shaped embodiment forcarrier and LEDs according to the present invention.

FIG. 21A is a reduced scale exploded perspective view of anotherexemplary embodiment according to aspects of the invention; here atriangle-in-cross section elongated form over which two curved flexiblecircuit boards, each carrying an array of LEDs, could be placed for usein simulating a fireplace fire.

FIG. 21 B is just the 3D shape circuit boards of FIG. 21A in isolation.

FIGS. 22A-DD are still frame stop action photographs from a continuousvideo of operation of one exemplary embodiment of a fixture similar tothat of FIG. 3 with a light engine similar to FIGS. 1A-D installed andoperating under the timing pattern at least similar to FIGS. 13 A-C.

FIGS. 23A-DD are a series of still frame color stop action photossimilar to FIGS. 22A-DD but with a front door to the fixture open to seethe light engine operating inside.

IV. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS A. Overview

For a better understanding of the invention, several examples of formsand embodiments the invention could take are now described in detail.These are by way of example only and neither inclusive nor exclusive ofall forms and embodiments the invention can take.

Frequent reference will be taken to the drawings which have beensummarized above. Reference numerals will be used to indicate certainparts and locations throughout the drawings. The same reference numeralswill be used to indicate the same or similar parts or locationsthroughout the drawings unless otherwise indicated.

It is to be understood that many of the embodiments will be described inthe context of what is called a light engine or module that essentiallyhas the form factor of a light bulb. It has a threaded base that can bethreaded into a conventional light bulb socket to provide electricalpower. Therefore, it can be substituted in virtually any light fixturethat has such a socket. It is to be understood, however, that theinvention can take a variety of other forms. It can be scaled up or downwithin practical limits. It does not have to be packaged with thethreaded conventional light bulb base. A different interface toelectrical power and a different mount in a fixture are of coursepossible. But as will be taught by the specific embodiments that follow,basic features and operating principles can be applied in a variety ofother form factors and applications.

It is to be further understood that the invention is not necessarilylimited to solid-state light sources. Other types of sources could bedriven in a similar regimen. Solid-state sources themselves can vary.Examples include LEDs, OLEDS, PLEDs, and laser diodes. They give offlight by solid state electroluminescence rather than thermal radiationor fluorescence.

It is particularly to be noted that multiple light engines, or oneintegrated light engine of 3D carriers of the light sources can beimplemented in a variety of applications which may or may not include anenclosing fixture. One example would be utilizing an embodiment of theinvention to simulate leaping flames in a fireplace. One example is atFIGS. 21A-B. This would involve designing the carrier to be elongatedacross a good portion of the fireplace. Alternatively, plural lightengines such as similar to those shown in FIG. 1A could be placed insome sort of an array across that same space.

It will be appreciated that even without a translucent cover or shroud,the light engine of FIGS. 1A-D, or other unshrouded configurations couldbe operated just for an aesthetically pleasing or other lightingpresentation. In one embodiment, using timing and sequencing such aswill be described further below, it can give the general appearance of asimulated jumping flame. The invention is not necessarily limited,however, to simulation of a flame. Again, it could simply present alight output effect.

B. Apparatus

1. Exemplary Embodiment Light Engine 10

a). Assembled Views of Light Engine 10 Self-Contained Bulb

With reference to FIGS. 1A-D through FIG. 15, one example of what wouldbe called light engine 10 will be described. In this example, its formfactor is larger than a conventional threaded base light bulb. Forexample, it can have an end to end length of 220 millimeters, and alargest diameter width of 90 millimeters, with a cylindrical at leastpartially light transmissive lens 12 having approximately 130 millimeterlength, an interior cylindrical three dimensional carrier 14 carryingplural LEDs 15, a top cap 16, and a bottom cap 18 with a threadedelectrical interface 19 (collectively having a length of about 65millimeters) (see dimensions in mm in FIG. 1B). But, as mentioned, thiscan be scaled up or down within practical limits. It can also havediffering form factors. For example, the diameter could be increasedrelative to length. The shapes do not necessarily have to becylindrical. In this embodiment the LED array is at least substantiallythree dimensional in that it projects light radially around thelongitudinal axis to at least a substantial degree if not entirely.Another embodiment is closer to the scale of a conventional incandescenthousehold light bulb. See FIGS. 23A-DD for an actual example. It is onthe order of 120 mm overall length, 50 mm overall width, and 70 mm fromtop cap to bottom of LEDs (see FIG. 13A for dimensions in mm of theflexible substrate 14 and LEDs 15 from that embodiment). Other formfactors are, of course, possible.

As such, light engine 10 can be a self-contained light source assembly.It can be assembled and sold as a unit. In this embodiment, itsuniversal threaded base allows it to be used in complementary threadedelectrical sockets typical in light fixtures that can be connected tohousehold line electrical power.

As will be appreciated from FIGS. 1A-D, this configuration allows360-degree light output radially relative the longitudinal axis betweenthreaded base 19 and top cap 16. This light output is through an atleast partially light transmissive (including but not limited tocompletely transparent, translucent, diffuse, colored, moire patterned,or other treatments on this lens, shroud, or cover). That cover 12 canalso be substantially sealed relative to the other components to protectinterior contents from moisture, dirt and dust, or other unwantedthings. In this embodiment, member 12 is basically a transparent coverover the LEDs to encase and protect them.

As can be further appreciated, the components can be made out of avariety of materials. In one example the threaded base 19 iselectrically conductive and thus typically metal. Other components suchas the formed end 18, top cover 16, and cylindrical carrier and outerlight transmissive cover 12 can be of electrically insulated material.One example would be any of a variety of plastics. The designer couldselect the materials according to need or desire. For example, forindoor applications, the materials may not need to be as robust as foroutdoors applications.

The shroud 12 in light engine 10 in FIGS. 1A-D alternatively could betranslucent. Non-limiting examples of translucent frosted or hammeredglass, oil paper, and some plastics.

LEDs or other light sources can be selected according to need or desire.In this example, the LEDs can be commercially available dies. They canbe selected from a wide variety of operating characteristics includinglumen output, light output distribution pattern, power requirements,color, etc. The designer could also elect to include either a thin layercoating that could change color of light output or othercharacteristics. The designer could also elect secondary optics at eachdie if desired. As can be appreciated, the designer can elect to use allthe same LEDs or LEDs that vary in characteristics. The designer wouldnormally evaluate all of those factors, including the color, lighttransmissiveness, and other characteristics of the cover 12, inselecting the light sources.

The LEDs in light engine 10 are characterized in FIG. 12, includingsize, color output, and operating requirements. It will be understood,however, that light source type and its operating characteristics canvary according the need or desire

As will be further discussed later, an internal drive circuit in lightmodule 10 can be configured to drive the LEDs in a certain pattern overtime. This programmed lighting regimen can take many forms.

As can be seen from FIGS. 1A-D, light engine 10 is elongated around anaxis generally between bottom cap 18 and top cap 16. Light from thesources will radiate generally radially from and therefore be observableby persons from any viewing position 360 degrees around that axis.Unlike the more 2D solutions, this promotes the perception of a realflame, as a real flame typically has 3D form.

b) Examples of Bulb 10 in Several Styles of Light Fixtures

FIG. 2A is a schematic illustration of a system according to the presentinvention. The light engine 10 of FIGS. 1A-D is mounted inside a lightfixture 20 which has a complementary threaded electrical socket (shownschematically in dashed lines). Fixture includes an intermediate frame22 that includes portions that are at least partially lighttransmissive. In this case, light engine 10 is shown in all dashed linesto indicate its general position inside the surrounding fixture 20 andthat light transmissive panes 24 of fixture 20 are frosted, hammered,and/or twisted or otherwise not transparent. These panes essentially arean outer shroud, cover, or lens. The observer of fixture 20 wouldtherefore not directly see light engine 10. Additionally, such frostingor texturing of the panes 24 (see for example FIG. 3) would helpsimulate a flame-like effect from the fixture.

As discussed with regard to light engine 10, its inner shroud 12 istransparent. But panes 24 on fixture 20 are translucent (here hammeredglass). Therefore, an observer of just light engine 10 would not be ableto image any LED with clarity. Rather, the translucent outer shroud(panes 24) would scatter the LED light in a manner that the observerwould perceive distorted and fuzzy images as the LEDs turn on and off insets along the axis of the shroud. The light output distributionpatterns, color, intensity, and other selected characteristics of theLEDs, in combination with the optical properties of the panes 14, wouldproduce the perception of a 3D flame burning inside light engine 10. Asubtlety of the design is that by intentionally obscuring the LEDs byhammered glass fixture panes 24, it actually enhances the simulation ofa flame.

Thus, placement of light engine 10 inside a fixture with frosted orhammered glass panes (such as FIG. 2A), enhances flame simulation. Anobserver from any available vantage point relative fixture 20 (e.g.front, left side, right side, and back side if exposed) would notdirectly image light engine 10 because panes 24 are translucent. Butthey would perceive a 3D diffuse and varying light output throughtranslucent panes 24. This enhances the perception of an actual flameinside.

As can be appreciated, fixture 20 in this example of FIG. 2A is onestyle of an architectural fixture. Its base 28 could include a mountinginterface (screws, bolts, or otherwise) for mounting it in an uprightvertical position on some supporting structure (e.g. wall bracket, post,bollard, horizontal surface mount, or otherwise).

FIGS. 2B and C show just a couple of non-limiting alternativearchitectural styles for fixtures (reference numerals 20B and C). Thisemphasizes how light engine 10 can simply be mounted into any number ofdifferent styles of fixtures. Furthermore, it can be understood that thepanes or at least partially light transmissive portions 24 of anyfixture could be transparent, or combination of transparent ortranslucent.

It is possible that panes 24 could be omitted and there be simplyopenings in fixture frame 22 to view the light engine 10. Thetransparent shroud 12 of light engine 10 would allow some viewing anglesto have a direct view of the LEDs. However, if shroud 12 were madetranslucent, it could diffuse the LED output and help simulate a flameeffect to observers even if there were no panes in the light fixture.Alternatively, there could be some other shroud, cover, or lens betweenlight engine 10 and the light fixture that could be translucent anddiffuse the light engine light.

It can therefore be seen that a system for simulating a flame effect cancomprise the combination of one, or more, light engines 10 operativelymounted in any of a number of styles of light fixtures 20. The realismof the flame simulation is enhanced by placing a translucent memberbetween the LEDs of the light engine and viewers of the apparatus. Inthis embodiment, the light engine can simply be threaded out andreplaced when needed. But when the light engine is installed in thefixture, the aesthetic can be that of a burning gas lamp. The 3D formfactor of light engine 10 furthers the simulation for virtually allviewing angles of the fixture.

c) Specific Example of Simulated Flame in One Fixture

FIG. 3 shows a similar fixture 20 to that of FIG. 2A. But this colorphotograph shows how frosted panes 24 on fixture 20 (essentially anouter translucent shroud), with transparent shroud 12 of light engine 10inside fixture 20, would present the observer with a fuzzy 3D ball ofbrightness inside fixture 20, which is similar to an actual 3D flame. Byon-off timing of sets of LEDs in the light engine, discussed below, thefuzzy ball of light would also appear to move, shift, expand, contract,and/or jump with licking flames at the top. Again, a subtlety of thedesign of this embodiment is that the observer intentionally is notallowed to image the light sources. Rather, the intentionally scatteringof light from the light sources (by hammered glass panes or shroud 24)helps create a perception in the observer consistent with an actualburning flame.

One aspect of certain embodiments disclosed herein is simulation of aflame. To help in understanding of one form in which this isaccomplished, FIG. 3 is a color photograph of an architectural lightfixture having a light engine such as FIGS. 1A-D inside. Light fixture20D includes a frame 22D outside of hammered translucent glass 24D (fourpanes at each side of fixture 20D) between a top 26D and a base 28D.This architectural fixture can take any number of forms and embodiments.As shown in FIG. 3, it has a light output from all four sides. Thehammered glass prevents direct view of the light engine 10 or individualLEDs 15 of light engine 10. As is indicative in FIG. 3, this singlemoment in time shows that the light output from light engine 10 isasymmetrical and flame like in appearance. By further discussion later,timing and sequence control of LEDs of light engine 10 and side fixture20D gives the appearance of a randomly lapping or jumping flame. Oneexample of such a timing sequence is illustrated in FIGS. 13A-C. Oneexample of actual operation of light engine 10 in a fixture 20 withhammered glass panes is shown in the stop action sequence of photos(color) at FIGS. 22A-DD and 23A-DD. These photographs give some betterunderstanding of the functional and aesthetic effect of operation ofthat combination for simulation of flame. FIGS. 22A-DD are sequentialframes of a video of continuous operation of light engine 10 inside thelantern-type fixture similar to FIG. 2A. They are 10 second continuousoperation taken at 30 frames/sec. Therefore each frame is approximately1/30″ of a second. They show visually and aesthetically how operation oflight engine 10 inside a fixture which itself has translucent glasspanes (e.g. hammered glass), produces the simulate appearance of aninternal flame or flames (see FIGS. 22A-DD). The sequence, timing, andbrightness of the lighting regimen of light engine 10 gives theappearance of flame(s) that jump around, flicker, build and retract, andthe like. For comparison, FIGS. 23A-DD show a 10 second continuousoperation of the same light engine at 30 frames/second but with a directview of light engine 10 (a door to one side of the fixture is opened sothat there is no hammered glass pane between the LEDs of the lightengine and the viewer). This illustrates how timing and sequence, aswell as intensity, of the LEDs can be controlled to simulate thechanging form factor of a real flame as it changes size, shape,direction, color, intensity, and otherwise when burning. Noteparticularly how a substantial number of LEDs are on more consistentlythan some LEDs higher up, and that the top-most LEDs are only flashed onat more spaced-apart times. This simulates the jumping, leaping, orlapping of flame tips. The lower-most LEDs, by either the number orintensity, tend to collectively pulse or seem to change intensity (andeven color). This simulates the more steady-state combustion at the baseor bottom of a flame (such as a gas flame) but also how it can tend tothrob or pulse. Note also how middle to top LEDs are controlled tosimulate flames leaping, jumping, or lapping by sequentially, at leastin part, being quickly turned on. This gives the perception of thesimulated flames produced 360 degrees around nearer the bottom or baseof the light engine periodically (pseudo-randomly) rising in height, andthen, even less frequently on average, turning on the very topmostspaced apart sets of LEDs on the light engine to simulate flame tipsevery so often. Still further, it will be appreciated that because theLEDs are mounted on a 3D substrate, even with the fixture door closed(FIGS. 22A-DD), because light from LEDs is emanating from around that 3Dsubstrate helps the impression or perception that the source of thelight is 3D, that there is a ball or volume of light. This enhancessimulation of a real flame. For example, FIGS. 23A-DD (fixture dooropen) demonstrate that even a viewer directly perpendicular to one sideof the fixture would be in line with some LEDs on the light engine. Butthe viewer would be off-axis many others. Therefore, the beam axes ofindividual LEDs would extend at various angles relative the viewer andhelp the 3D perception. Still further, a viewer aligned with the cornerof the fixture would see part of the light from the light engine insidethrough at least two hammered class panes 24. This helps the 3Dperception. Also, in operation, light from the light engine wouldemanate in radial directions all around the vertical longitudinal axisof the light engine, so that viewers from any radial direction wouldhave similar visual experience. But refraction and reflection of thehammered glass panes would also contribute to somewhat random patternsor luminance from the fixture, which also further enhances theaesthetics and simulation. For example, some light from LEDs on a sideof the light engine opposite the one viewer's viewing direction wouldemanate first away from the viewer but could hit the inside of thehammered glass pane nearest to it and reflect instead of pass throughthat pane on the opposite side of the fixture. It might reflect to oneof the panes on either side of the fixture relative the viewer. It couldeven bounce around inside the fixture. In any event, this type ofreflected light may reach another pane, including the one closest theviewer. This further enhances the perception of 3D source of luminanceinside the fixture. As will be appreciated, this perception of a 3D ballor body of flame will be the same or similar from all viewing directionsof the fixture of FIG. 3, or FIGS. 22A-DD.

But as can further be appreciated, as an alternative, cover or shroud 12right at the LEDs of light engine 10 could be translucent (otherwiselight diffusing) and the pane or panes 24 of light fixtures such asFIGS. 2A-C could be transparent or missing. The viewer would not have adirect view of the LEDs and would see a 3D source of luminance thatwould appear to change size, shape, and nature in a random way,including the expanding/contracting and jumping or lapping flame tips.If the fixture has panes, even if they are transparent, at least some ofthe light will bounce around (by reflection at the inner surface of thetransparent pane or parts of the fixture) or be refracted (at both innerand outer surfaces of the transparent pane). This may enhance thesimulation of a flame. This can help the light engine to be retro-fittedand used in fixtures that do not have translucent panes, shrouds, orlens.

It is also possible that a light engine with a transparent shroud 12 beused in fixtures with transparent panes, shrouds, or lenses, or nopanes, shrouds, or lenses. Operation of the light engine would stillproduce the pseudo-random light output which is designed to havecharacteristics that simulate an actual flame as described above. Thisis especially true when viewed from substantial distances, as lighttends to disperse with distance. Visual acuity also degrades.

2. Exploded or Isolated Views of Components of Light Engine 10

The internal parts in the assembly of light engine 10 are illustrated inFIGS. 4A-B through 7A-D.

FIGS. 4A and B show the main components of light engine 10 in explodedform. As can be seen, threaded cap 19 can be mounted on bottom cap 18.Bracket 30 can be mounted inside bottom cap and support a transformer32, the cylindrical LED carrier 14, the concentric cylindricaltranslucent shroud or lens 12, and a control circuit 34. A top cap 16can fit onto the open top of shroud 12 to complete the assembled unit.

FIG. 5 is a cross-section of FIG. 4B and gives more details of placementof the components inside light engine 10.

a) LED Carrier (Flexible Circuit Board and LED Array)

FIGS. 6A-C are perspective and isometric views of LED carrier 14. Inthis embodiment, carrier 14 is cylindrical in shape (cylindrical sidewall with open opposite ends) and is populated with LED dies around itssidewall. In this embodiment this 3D shape is made possible by using aflexible circuit board from the cylinder with pre-printed circuit traceson its outer surface. LEDs are then surface-mounted to appropriatepositions in that printed circuit. FIG. 11 gives one general example ofwhat such a printed circuit board might look like in plan view. Flexiblecircuit boards are commercially available.

It this specific embodiment, the LEDs 15 are populated fairly evenlyacross most of the cylinder's outer surface from near the bottom orbottom cap open end towards the top or top cap open end. Note that hereseveral clusters of LEDs 15 at or near the top extend nearer the top.The clusters are spaced apart circumferentially. This allows creation of“licking” or “lapping” flame tips at certain areas of carrier 14. Thisembodiment has the LEDs relatively heavily populated on the substrate,with the exception at the top.

Spacing of LEDs 15 in this example are shown in FIG. 13A (dimensionnumbers in mm). Thus, the cylinder is relatively heavily populated withLEDs. As can be appreciated, the designer can adjust the spacing andalignment of any set of LEDs. The figures give examples of such spacingin proportion to the scale of the light engine or substrate. It's to beunderstood that the figures are not to scale. Therefore, as shown inFIG. 1B, the height of the substrate for that embodiment of light engine10 is approximately 130 mm. Thus FIG. 1B shows spacing of the LEDs 15relative to one another for a form factor and size as dimensioned there.On the other hand, FIG. 13A shows a circuit board for a light enginelike that of FIG. 1A-D, but roughly half as big. The specific spacingsbetween LEDs, as well as the consistent 51 degree diagonal angle alongwhich most of the LEDs are aligned, can be derived by the dimensionsannotated on FIG. 13A (in mm). Note that other figures, such as FIGS. 16through 21, illustrate other potential sizes and form factors. Thespacing of LEDs can vary according to need or desire. The designer canalternatively adopt more of the arrangement of FIG. 13A, which isheavily populated with consistently arranged LEDs from bottom towardsthe top but ends up around the top with small separated clusters ofLEDs. This can help give the appearance of a lapping or jumping flame.For example, simulated Christmas tree shapes (e.g. FIG. 20) might be afew inches tall to many feet tall. Likewise, some of the other shapescould be the same. Some could be many feet tall (e.g. lawn displays orsculptures). These Figures are not intended to illustrate the precisenumber or spacing of LEDs, but rather general locations.

By automated manufacturing processes, the circuit board, printed traces,and LEDs can be assembled relatively efficiently and economically formass production. This represents a minimal number of parts andmanufacturing steps.

The material of carrier 14 can vary. In this embodiment it is opaque,flexible circuit board material (e.g. dielectric) and is commerciallyavailable. It will be appreciated, however, that 3D shapes could beobtained with flat or rigid circuit boards assembled appropriately.Also, carrier 14 could be light transmissive (translucent ortransparent) in areas without electric traces or LED dies. It also couldbe reflective in those areas (e.g. reflective paint, coating, orsurface). One example would be white surface.

It will be further appreciated that the carrier can be elongated in ahorizontal operation direction, asymmetrical, or in almost any shapethat has a peripheral surface from a lower end to an upper end overwhich light sources can be populated and operated.

b) Bottom Cap and Threaded Base

FIGS. 6D-F show details of bottom cap 18 and threaded base 19. Threadedelectrical base 19 can be fixed to a formed nose portion 40 on thebottom of cap 18. This can be by interference fit, adhesives, rivets,screws, or other fastening techniques such as are known in the art.Electrical leads from threaded base 19 to the interior would also beadded (see FIG. 6H). Cap 18 can be a dielectric (e.g. certain plastics)and base 19 an electrical conductor (e.g. conductive metal). Examples ofthreaded base include but are not limited to E14, E27, E40, and B22.

As can be appreciated by those of skill in the art, heat managementfeatures can be incorporated into light engine 10, including bottom cap18. For example air vents or openings can be formed in bottom cap 18 topromote air transfer and carrying away of heat from LED operation. Ventsor openings could also be formed in top cap 16. Having them in both topand bottom caps could enhance such heat transfer by convention away fromthe LEDs. The vents or openings could be relatively small to allowgaseous state (air) transfer but deter liquid or solid state transfer(water, dirt, debris, insects). There could also be heat transfer fromthe LEDs by conduction through the circuit board and then the top and/orbottom caps.

c) Internal Bracket to Hold Transformer and Shroud

FIG. 6G shows in isolation a bracket 30 used in assembly of light engine10. Bracket 30 (see also FIG. 6G) could be screwed, riveted, orotherwise fastened to bosses 46 inside bottom cap 18 (see FIGS. 6D andE) through apertures 33 and bottom cross piece 32 of bracket 30 (seeFIG. 6G). An electrical transformer 32 could be mounted to bracket 30(see FIGS. 4B and 5). Transformer 32 would convert typical householdline voltage (e.g. 120 VAC) to a voltage useable by control circuitry34, discussed below (e.g. 12 VDC; see FIG. 6H). Device 32 can take aforms that are commercially-available from a number of sources. Its formfactor would be such that it would fit into bracket 30, the size ofwhich can be deduced by comparison to threaded base 19.

Bracket 30 also will support shroud 12. As can be appreciated from thedrawings, shroud 12 would fit concentrically over LED carrier 12 betweenbottom and top caps 18 and 16. Shroud 12 spacing from carrier 12 isshown in FIG. 5 (the difference between diameter D2 of shroud 12 anddiameter D1 of LED carrier 14). This can be a fraction of an inch.

At its end opposite cap 18, bracket 30 additionally supports a controlcircuitry 34 that would operate the sequence of LED activation (seeFIGS. 4A, 6H, and 61). Control circuitry 34 can be attached (e.g.screws, bolts, rivets, or other techniques) to that end of bracket 30.Operation of circuitry 34 will be discussed in detail below.

Bracket can be of metal (e.g. aluminum) or possibly of other rigidmaterials sufficient to support the components described.

Cylindrical internal LED carrier 14 can have mounting holes 45 (see FIG.6A) that align with apertures 35 on opposite sides 34 and 36 of bracket30 (see FIG. 6G). By rivets, screws, bolts, or other fasteners, thiswould fix carrier 14, with its plural LEDs 15, to bracket 30, which inturn is fixed to bottom cap 18. Circular circuit board 50 (FIG. 6I) caninclude a top side 52, a bottom side 54, through holes 53, a perimeteredge 56, and electrical components 58. This circuit board component 34can be mounted by screws, rivets, or other fasteners through openings 53to the openings 39 along the top 38 of bracket 30 (see FIG. 6G).Appropriate electrical connections from conductive base 19 to circuitboard 34 (see FIG. 6H) would be included.

d) Shroud

FIGS. 7A-C illustrate in isolation the basic form factor of outer lensor shroud 12. Like carrier 14, it is a cylinder with opposite open ends.

Cover or lens 12 can be slid down over the foregoing combination and itsbottom end 62 seated on a complementary flange and ledge at the top ofbottom cap 18.

The nature of shroud 12 in this embodiment is a transparent cover overthe 3D array of LEDs. As mentioned, in some embodiments, shroud 12 couldbe translucent. Translucency can be obtained in a number of ways.Several non-limiting examples are materials which can be frosted,textured, moire patterned, or otherwise configured so that directimaging of the LEDs is not possible with the human eye.

It is to be appreciated however, that light engine lens or shroud 12could have other or different optical properties.

As mentioned previously, in this embodiment a translucent shroud hasbeen found to enhance simulated flame appearance. To do so with lightengine 10 with a transparent shroud or cover 12, another shroud, thisone translucent, would need to be placed between light engine 10 and theviewer(s). As discussed above, one way is to mount light engine in afixture that has such a translucent shroud. Non-limiting examples arepanes, a cover, a shroud, or a lens. It is not necessarily requiredhowever. As mentioned, embodiments could simply be used to essentiallyhave a light show or aesthetically pleasing lighting effect. In othercases there may be a distance from normal viewers or pre-existing layers(e.g. glass doors to a fireplace) that would allow one form of the lightengine to produce a reasonable or good simulated flame effect without ahammered glass or similar translucent shroud.

Thus, any of the embodiments described herein could have a substrate ina 3D form factor populated with LEDs, and the LEDs operated in apre-programmed timing sequence. It could be just be aesthetic or othereffect. Or the timing sequence could follow the pseudo-random flamesimulations, the same or similar to discussed above, by having a pulsinglower portion and pseudo-random traveling upward to simulated flametips, all just with LEDs and no cover, shroud, or lens. Alternatively,the cover, shroud, or lens right at the LEDs could be translucent orotherwise light diffusing. Or that shroud, cover, or lens could betransparent and another shroud, cover, or lens (e.g. panes) couldbetween the light engine with transparent shroud and the viewers. It isalso possible to have a translucent shroud at the light engine andanother translucent shroud over that. Furthermore, the shape of shroud12 covers the output light distribution patterns of the LEDs in thearray inside light engine 10. In this embodiment, this means shroud 12is elongated along the longitudinal axis of light engine between bottomcap 18 and top cap 16, and thus, emits relatively unaltered light fromthe 3D LED array radially all along that axial length. This allows flamesimulation in both a 3D form and from 360 degree viewing angles radiallyfrom the axis.

Because light engine 10 of this embodiment would typically be used forflame simulation, and this embodiment operates the LEDs to simulate aflame jumping in the direction of top cap 16, light engine 10 istypically mounted threaded-base-down. However, as will be appreciated bythose skilled in the art, if base up operation were desired, the on-offsequence could be inverted by appropriate configuration of the controlcircuit.

And, it is not required that light engine be operated with itslongitudinal axis vertical.

e) Top Cap

FIGS. 7D-G are perspective and isometric views of top cap 16. It couldbe by interference fit, snap-fit, adhesive, screw-threads, screws,bolts, sonic welding, or other techniques. It can be beneficial for itto be removable (e.g. for maintenance and repair). But it can also bebeneficial that it at least substantially seal the top of shroud 12. Forexample, by the fastening method or with such things as gaskets, rings,or other seals, light engine 10 can be made robust including foroutdoors use where moisture, dust, or debris can be an issue.

FIGS. 7D-G show top cover 16. It has a body 70 with a peripheral annularflange in shoulder 72. Its interior side includes projected bosses 74.This allows cover 16 to be complementarily fitted into the top end ofcylindrical lens 12.

Therefore, as can be appreciated, assembled light engine 10 (see e.g.FIGS. 1A-D) can be self-contained including plural light sources on thethree dimensional carrier with appropriate on board electronics. Powerwould be delivered through threaded base 19. Installed base-down in anelectrical socket, either on its own as in FIG. 1A or in a fixture as inFIGS. 2A-C, it can be operated to simulate a burning flame. Viewers fromavailable vantage points 360 degrees around it will see essentially aconsistent simulation. The simulation will therefore have bothflame-like appearance but also a 3D realism.

f) Control Circuitry

FIGS. 8-11 illustrate generally how the control circuitry 34 of FIG. 6Ican be configured and how the printed circuit on LED carrier can beproduced. It is to be understood that this is but one example only ofthe circuitry that could be used on circuit board 34.

FIG. 8 shows a block diagram of the main components of control circuitry34. Control circuitry 34 in this example is centered on a programmablemicrocontroller or CPU 101. CPU 101 would receive appropriate electricalpower (e.g. 12 VDC) from transformer 32 (FIG. 6H) through power filtermodule 102 and power regulator module 103.

FIG. 9A shows power module 103. It is a low-dropout linear regulator setto 5.0V output. The output VCC can power the DMX module interface 105,see FIG. 9B, the CPU module 101 and CON4, see FIG. 9C, and CON3, seeFIG. 9E, 9F, 9G. The power module input is 12V via a 2-pin powerconnector that would be connected to transformer 32 of FIGS. 4A-B.Transformer 32 converts 120 VAC to 12 VDC. The 12 VDC output fromtransformer 32 feeds control board 34, including CPU 101, LED PWM drivermodules 104, and each LED zone. Transformer 32 may be a transformer, atransformer and solid-state hybrid, or a solid-state only device.

Power filter module 102 can be any of a variety of filtering techniquesto help manage typical household voltage. Those skilled in the art couldselect the type of filtering and voltage regulation deemed needed ordesired for a given light engine according to the invention.

FIG. 9B shows what is called DMX module or interface circuit 106. U15 isa monolithic integrated circuit designed for bidirectional datacommunication on multipoint bus-transmission lines. U15 is designed tofunction on balanced transmission lines and meets ANSI StandardEIA/TIA-422-B and ITU recommendation V.11. An example is the TexasInstruments SN75176. U15 interfaces with the control module at pin 32,see FIG. 9C, via DMX-CON on pins 2 and 3 of U15. U15 pins 6 and 7terminate at CON3 (DMX). DMX module 106 therefore allows for a varietyof things. One would be the ability to do such things as have a remotecontrol of on/off of the light engine. Another would be remote controlof speed, size, intensity, or other controllable factors of operation ofthe light engine. Another possible optional feature would be remotecontrol of either operating the light engine according to the timing andsequencing algorithm for simulated flame effect or simply turning allLEDs on at some same or similar intensity. This option could allow auser to switch between a simulated flame effect, such as simulating agas lamp wall-mounted porch fixture, with a simulated appearance of therandomly jumping gas flame inside the fixture, but then turning alllight sources full on for use as a more conventional constant on porchlight. Alternatively, the circuit could be configured to allow a manualswitch between such states. DMX protocol could also allow such things asremote programming of the light engine. For example, by knownmethodologies associated with DMX protocol and communication, differenttiming and sequence operations could be added or changed over in a lightengine without hardwire communication or carrying the light engine down.

FIG. 9C is a schematic of CPU 101. It implements the LED driving regimenwith its programming. CPU module 101 may be controlled and/or programmedvia DMX module or the ISP interface. The control module 101 may alsoallow limited control for speed (ADC1) and flame size (ADC2), see FIGS.9E-F. The control module can sense when a human being is near utilizinginfrared body induction, see FIG. 9G. This can be used to turn thedevice 10 on when sensing someone's present, or off when not detectingsomeone's presence.

As can be appreciated, control circuitry can be programmed to operatetiming, sequence, intensity, or other operating parameters of individualLED sources. This could include simulation of flame size and speed. Inother words, the speed of sequencing of on and off of certain LEDs tosimulate the speed of lapping flames could be sped up or slowed down.Also, there could be selectivity as to which LEDs are turned off and onrelative from bottom to top to affect at least the appearance orsimulation of height of flame for a given array of LEDs. As can befurther appreciated, this can be programmed into a light engine on aone-time basis. Alternatively, by techniques known in the art, it can bechanged by reprogramming. There could also be several different flameeffects preprogrammed into a light engine and some sort of selectionability to choose between them from time to time. Furthermore, therecould be added some adjustable control (manual or wireless) that wouldallow a user to tweak operating parameters such as flame height andspeed. This would give the user control of preferred aesthetic operationof the light engine.

Control module 101 is an 8-bit microcontroller. Control module 101 hasthe following features: A Nested interrupt controller with 32interrupts. Up to 37 external interrupts on 6 vectors. 2×16-bit generalpurpose timers, with 2+3 CAPCOM channels (IC, OC or PWM). 16-bit, 4CAPCOM channels, 3 complementary outputs, dead-time insertion andflexible synchronization. 8-bit basic timer with 8-bit prescaler. Autowake-up timer. Window and independent watchdog timers. UART with clockoutput for synchronous operation, Smartcard, IrDA, LIN. SPI interface upto 8 Mbit/s. I2C interface up to 400 Kbit/s. 10-bit, ±1 LSB ADC with upto 10 multiplexed channels, scan mode and analog watchdog I/Os. Up to 38I/Os on a 48-pin package including 16 high sink outputs. Highly robustI/O design, immune against current injection

Driver module(s) 104 (FIG. 9D) would take output from CPU 101 drive theLEDs according to a pre-programmed regimen in CPY 101. Such driversgenerate the needed driving power to the whole array of LEDs accordingto instructions of CPU 101. As will be appreciated, drivers 104 arepulse-width-modulated drivers. This allows quite precise control ofbrightness of LEDs. This technique is well-known.

g) LEDs

FIGS. 10 and 11 illustrate how plural LEDs can be produced for lightengine 10.

FIG. 10 illustrates an electrical schematic 110 for one example of anarray of 132 LEDs and how they could be controlled in sub-sets by CPU101 (see PWM inputs related to CPU 101). Of course, the number of LEDscould be higher or lower according to need or desire.

FIG. 11 is a plan projection of a printed thin layer conductive circuitof the type that could be used to surface print the circuit 110 of FIG.10 onto a flexible circuit board (here show in plan view), that couldbent into cylindrical carrier 14. As can be appreciated, in some cases asingle flexible circuit board could carry the circuit and LEDs for theentire 360 degrees array. In other cases two or more flexible circuitboards could each carry a part of the overall circuit and LEDs, and thetwo or more flexible boards shaped into a cylinder. Still further amulti-plane or multi-facet non-flexible circuit board or substrate couldbe formed into the 3D form factor desired and include the printedcircuit.

As can be appreciated, the precise number of LEDs, their placement, andthe electrical components and circuitry related to them, can varyaccording to need or desire.

It is to be appreciated that the circuitry allows both pulse widthmodulation of driving electrical power to be adjusted to each LED and inconcert or in coordination with other LEDs.

FIG. 12 provides details about the types and characteristics of LEDsthat can be used in the embodiment of light engine 10. Suchcharacteristics are well-known to those of skill in the art. It is to beunderstood, however, that any or all of those characteristics may bevaried according to the designer's need or desire. Such LEDs areavailable commercially from a number of sources.

As can be appreciated by those skilled in the art, the designer couldselect from a variety of options regarding the light sources. Forexample, LEDs come in a variety of different form factors, packages,mounting tape techniques, power usage, size, light output distribution,and color or color temperature. All LEDs for a given light engine mightbe the same in all operating characteristics. On the other hand, thedesigner could select differences between LEDs in the same light engine.In one example, LEDs of different color temperatures could be placed atdifferent positions to try to enhance simulation of actual flames.Actual flames tend to have different color at different portions atdifferent times. For example, different color temperature LEDs could beat the very top of the LED array for the tips of the lapping flames ofthe simulated flame whereas perhaps different or deeper yellows,oranges, or reds could be distributed lower down. And, of course, if notsimulating a flame effect, any color temperature LEDs might be selectedaccording to the designer's choice for an aesthetic effect.

C. Method of Operation

As can be seen from the foregoing, light engine 10 is a self-contained,replaceable light source assembly. It can project light from the threedimensional carrier 14 through lens or cover 12 in all radialdirections. Combinations of LEDs can be turned on at certain times. Thespeed of on/off of the combinations, which LEDs are turned off and on,and intensity or brightness can be adjusted through programming of CPU101.

FIG. 13A illustrate one specific example of a lighting regimen for lightengine 10. FIG. 13A is based on a flexible circuit board with subsets ofLEDs arranged as shown. Each subset is designated by a number between 1and 16. For examples there are three subsets “1”, each having three LEDs(each shown by a small circle with cross hairs). Each of subsets “1” isspaced along the top of the circuit board. In comparison, three subsets“16”, each with two LEDs, are spaced apart along the bottom of thecircuit board. The chart below shows the timing diagram that can be usedfor one cycle of LED operation. Once the sequence of Chart 1 iscompleted, it would repeat for as long as light engine 10 is operating.

TABLE 1 Sequence in Time LED subset/status of operation 1 14/FB;15/FB/16/FB, 11/LB 2 11/FB; 12/FB; 13/FB 3 8/FB; 9/FB; 10/FB 4 8/off;9/off; 10/off; 5/FB; 6/FB; 7/FB 5 5/off; 3/FB; 4/FB 6 11/off; 6/off;1/Fb; 4/FB 7 1/off; 3/off; 4/off; 7/off; 11/FB 8 12/off; 13/off/8/FB 98/off; 5/FB/9/FB; 10/FB 10 9/off; 10/off/2/FB; 6/Fb; 7/FB 11 2/off;5/off; 7/off; 3/FB 12 11/off; 3/off/6/FB; 13/FB 13 12/off; 11/off; 13/FB14 8/off; 10/off; 12/FB 15 8/off; 10/off/12/FB 16 13/off/9/off;6/FB/2/FB 17 2/off; 5/off; 3/FB; 13/FB 18 11/off; 13/off; 1/FB 19 1/off;3/off/12/FB; 11/FB; 13/FB

-   -   Key: “FB” means the LEDs are at full instructed PWM brightness;        “LB” means PWM non-full or low brightness; and “off” means        completely off.

By referencing Table 1 above in combination with FIG. 13 A and FIGS. 13B-C, a graphic approximation of how one timing and sequence forsimulated flame effect can be created is illustrated. Assuming an LEDarrangement such as FIG. 13A (shown in plan view and not in its finalthree-dimensional shape), and assuming subsets of the 99 LEDs shown inFIG. 13A are given the numbers 1 through 16 on that figure; where threesubsets of three LEDs each are separated into groups at 1, and othersets are distributed at 2 through 16 moving down numbers. FIG. 13B thenshows, top to bottom, timing of on and off of subsets of LEDs and stateof intensity by different colors according to Table 1 above. FIG. 13 Cillustrates each sequence 1 through 19 individually and one-at-a-time.By looking quickly through each sequence 1-19 in FIG. 13 C in series,one gets a general understanding of this algorithm of LED operation forsimulation of flame effect.

In particular note how sequence 1 (FIG. 13C) starts by illuminating thebottom two rows at different intensities. Succeeding sequence states 2,3, 4, 5 and 6 basically sequentially turn on succeeding vertical subsetsupwards to the top. Thereafter, there is a jumping around of verticallevels that are illuminated or not (sequences 8-19), with only onesequence illuminating the topmost sets of LEDs 1. After sequences 1through 19 (which occur rapidly), it repeats. It basically presents apseudo-random firing of different LEDs in a kind of jumping or lappingsimulation. The different intensities enhance this pseudo-randomness andstereoscopic type appearance of three-dimensional depth of the flameeffect even though in some embodiments the LEDs output is constrained tothe exterior of the three-dimensional shape. In other words, even thoughone cannot see LEDs on the other side of the shape, there is still aperception of three-dimensional depth of the output from one viewingdirection. As will be mentioned later, the substrate could itself betransparent or translucent and allow some see-through to light output onopposite sides of the three-dimensional shape. But this is not required.

Table 2 indicates lighting period (length of lamp being on) of each lampin a single cycle:

As can be appreciated, this timing sequence coordinates on/off ofcertain LEDs all around light engine 10. As indicated at Table 1, thiscan simulate a flame by simulating not only intensities varying overtime but also the flame jumping in height over time.

TABLE 2 Longest period Shortest period Top-most end 1.44 ms 320 msBottom-most end 1.44 ms 560 μs

All output signals listed above are PWM output signals. PWM controldigitally saves costs and power consumption. Spaces between LEDS can beincreased or decreased proportionally, or more or less LEDs can be usedper given area. Color temperature of LEDs in this embodiment can bewithin 3 color temperature ranges, depending on demands of end-users oraccording to a designer's wishes: 180K-2000K (redder); 2000K-2200K(red-yellow); and 2200K-2400K (yellower). Light emitted form LEDs isscattered or refracted in order to irradiate softly, achieving the flameeffect. However, these parameters can differ according to needs ordesires.

As can be seen by the foregoing, PWM control regulates energy flow tothe LEDs to control brightness as well as when they are on or off. Eachrepeating cycle of the timing sequence of Table 1 generally turns “on”several subsets of LEDs near the bottom for a brief period, and thensequentially turns “on” and “off” subsets higher and higher untilSequence step 6 in Table 1 has the top-most subsets all on at fullbrightness, as well as a few subsets (subsets “4”) immediately below atfull brightness them off while turning LEDs. The “on” subsets jumps backdown towards the middle (see Sequence steps 7-15), and then builds backto the top (steps 16-18) before dropping way to bottom (step 190). Thisbuilding up, then falling back, building up, and then falling way back,in repeating cycles, simulates the jumping of real flames, including thelicking or lapping of upper flame tips.

At the relatively short time durations of each cycle, the observer wouldget the perception of jumping flames. And this would be from anyavailable radial viewing direction.

It will be appreciated by those skilled in the art that the exact timingsequence could vary, including by the designer's desire and need. Thesequence can be programmed into CPU 101 by conventional techniques. Uponinstallation of light engine 10 to an electrical socket, and electricalpower to light engine by an on-off switch to the socket, CPU 101 wouldautomatically begin the cycling of the sequence of Table 1 and continueas long as power is provided to the socket.

One example of a regime for driving the LEDs is shown at FIGS. 22A-DDand 23A-DD. As discussed earlier, a light engine similar to that oflight engine 10 of FIGS. 1A-D is used. It has a flexible circuit boardshaped in a cylinder with the LED layout similar to FIG. 13A. There is atop level of LED groupings spaced apart for flame tip effect (like LEDgroups 1 of FIG. 13A). There are five levels below that: LEDS 2 and 3;LEDs 5 and 6; LEDs 8 and 9; LEDs 11 and 12; and LEDs 14 and 15. In thiscase, the sequence, order, and intensity of driving of the differentLEDs is illustrated in the time-lapse color photos.

As indicated above, light engine is capable of re-programming. Not onlycould a different timing sequence be installed, the speed of each cycleand the number of levels of LEDs operated could be changed. This wouldallow a faster or slower flame jumping and a taller or shorter flame.

D. Options and Alternatives

As mentioned, the invention can take many forms and embodiments.Variations obvious to those skilled in the art will be included with theinvention, which is not limited by the embodiments discussed herein.

1. Different Forms of Light Engines

For example, light engine 10 can take different form factors. Asmentioned previously, different populations, arrangement, and types oflight sources are possible. Different driving regimes are possible. Thelight engine can carry on-board a shroud, cover, or lens that istranslucent, or it can be transparent, or a combination. It does notnecessarily have to have a shroud, cover, lens, or the like.

a) Different Types of Light Fixtures

FIG. 14 gives additional non-limiting examples of light fixtures withwhich light engine 10 could be used. They include fixtures supported ontheir bottom or base (such as could be column, bollard, orpost-mounted); fixtures supported on their side (such as for wall orpost mounting), and fixtures supported or hanging from their top (suchas pendant lights or chandeliers). Some may not allow viewing from alldirections, or even 360 degrees in the horizontal plane (e.g. awall-mounted light). But the light engine or LED arrangement is suchthat it has 3D effect and enhances simulation of flame effect foravailable viewing angles.

b) Alternative Bulb-Form with Screw on Top Cap

FIG. 15 shows an alternative light engine 10B. It could include a base19 like light engine 10. Base 19B could be of various sizes. Theelectronic circuitry could be mounted in lower cover 18B instead of nearthe opposite end. Cover 12B could be like cover 12 of light engine 10.It could be clear plastic or glass hammered or frosted glass. In thisembodiment top cover 16B could also be clear plastic, glass hammered, orfrosted glass. It could snap in or screw into the top of cover 12B.Other variations are, of course, possible.

c) Flame-Shaped Bulb

FIG. 16 shows another form factor for the light engine. This example 10Chas a screw-in base 19C and base 18C with driver and controller. Itscarrier 14C is three dimensional but follows in a complementary anexterior hammered glass envelope 12C that is roughly shaped like aflame. Plural LEDs 15C could be distributed either on a similar threedimensional shape to the outer glass envelope. Alternatively, the LEDscould be mounted along radial extending fins of the carrier. This wouldstill result in a three dimensional distribution of LEDs inside theglass envelope.

d) Double-Cylinder LED Carriers

FIGS. 17A and B show another possible alternative. Instead of onecarrier 14 on which plural LEDs 15 are distributed, a set of concentriccarriers 14A and B, each having their own plurality of distributed LEDs15A and B, could be mounted inside the light engine. As can beappreciated, at least carrier 14 (outer) could be made of a materialwhich is at least partially light transmissive. The inside carrier 15(inner) could be also. This could therefore add further perception ofthree dimensional depth of the simulated flame by having lightoriginating at different distances from the longitudinal axis of thelight engine and outward. The viewer would see not only LEDs 14 (outer),but 15 (inner). As noted in FIGS. 17A and B, instead of the staggeredLEDs such as shown in FIG. 6A, the LEDs could be arranged in uniformrows and columns around each cylinder. The rotation of each cylindercould be adjusted according to need or desire. But, of course, thestaggering or other distribution patterns are possible.

2. Other Polyhedron Forms (Stars, Domes, Cones, Etc.)

FIGS. 18A and B illustrate another form factor for carrier 14. In thisexample, carrier 14D has a star shape cross-sectional perimeter. It canbe symmetric or does not have to be symmetric. LEDs could be distributedout at the long perimeter vertical edges, and/or along recessed verticaledges, and/or along intermediate portions between those inner and outeredges. Again, they could be placed in a linear pattern or otherwise.Carrier 141) could be clear or solid plastic formed into the starconfiguration. The LEDs could be placed on peaks and valleys or also onside panels.

Conforming translucent shrouds can cover each of the 3D shapes. Again, atranslucent shroud can enhance the flame effect by diffusing lightoutput of the individual LEDs to create an appearance of more of theball or volume of light or luminance. The jumping around in variousintensities, including in the embodiment described above relative toFIGS. 13 A-C, include the simulation of the ball of light jumping up anddown and periodically spiking at flame tips. The designer can selectbetween optical characteristics of such a shroud according to need ordesire.

FIG. 19 shows a still further variation for the carrier 14. In thiscase, carrier 14E has peaks and valleys like that of embodiment 14D.However, this “star dome” shape has many more radial projections and adomed top. Again, this form factor can be operated as shown.Alternatively, a translucent shroud could be placed at or near(essentially over) the LEDs and substrate.

FIG. 20 shows a still further optional embodiment. A cone 14E for thecarrier can have LEDs 15E distributed as shown.

3. Fire Place Fire Simulator

FIGS. 21A and B illustrate a still further optional embodiment of theinvention. A three-dimensional form or base 120 is elongated in thehorizontal direction and somewhat triangular in cross-section. Circuitboards 14L and 14R, each carrying an array of LEDs, can be mounted onopposite sides of base 120. Necessary components analogous totransformer 32, and control circuitry 34 (e.g. CPU 101, power management102/103, PWM driver(s) 104, and possibly others) could be located insidebase 120 in total or partially.

According to similar operational principles discussed above, the LEDs15L and 15R on both boards 14L and 14R could be operated to simulate ajumping flame all along the base 102. This still has a 3D effect in thatviewers from almost any viewing direction would see plural LED surfaces.It also can follow an analogous timing sequence top to bottom fortogether simulating flames of a fire in a fireplace.

A translucent shroud may be placed over the LEDs in an analogous way tothe other embodiments.

As can be appreciated, and as mentioned earlier, the operation sequenceof the individual light sources in a light engine can be programmedaccording to need or desire. This can include different patterns,different speed, different heights, and potentially different colors. Inone example, the substrate could be populated with LEDs of differentoperating characteristics. One of them could be different colors. Theprogram could take advantage of the different colors to enhancesimulation of the subtle variety of colors of actual flames.Alternatively, programming might change which color of LED is turned onat different times in the same sequence steps. In other words, some LEDsof one color can be turned on at a first step in a first cycle. LEDs ofa different color at that same step in a second cycle.

The determination of whether a shroud is used or not is within thediscretion of the designer. Again, it has been found that a translucentshroud can enhance simulation of a flame appearance.

Another potential option is to install several independent sets of LEDson the same substrate. Each set could be distributed around the threedimensional substrate shape. Either by a separate timing circuit or byappropriate driving of the different sets from the same control circuit,the same light engine could operate simultaneously two or more circuitsof LEDs. This could also enhance simulation of a flame by further givingthe pseudorandom effect by now multiple separately timed circuitsoperating concurrently on the same light engine. As indicated in some ofthe figures, alternatively separate circuits could be operated in anested relationship spatially and have transparent or translucentsubstrates so that when operated concurrently, the user sees the lightoutput sequencing of all the plural nested sets of LEDs. An example isshown at FIGS. 17A and B. And, of course, multiple sets of separate LEDcircuits and three-dimensional substrates can be positioned essentiallyas modules adjacent each other instead of on one substrate. This couldallow building of light engines of various lengths, heights, or widthsby adding or subtracting such modules. For example, in the fireplaceusable embodiment of FIGS. 21A and B, the single substrate shown inthose figures could instead be split up into plural sections that aremounted on top of the three-dimensional triangular form factor base orhousing. Or, alternatively, there could be plural devices that could bepositioned end to end to extend the length of the overall device. Therecould be structure that allows interlocking or removable fixation of themodules which could include such things as adhesive, hook and loopfasteners, interference fit male and female connectors or hardware suchas screws, bolts or the like.

Still further, there could be more than one timing device per lightengine. The user could select between the two or the different devicescould operate different LEDs. The different timing devices or circuitscould operate different sets of LEDs as previously described. Differentsets could vary also in their spacing from one another, their color,their timing, their intensity, or other operating parameters.

As has been mentioned, an option would be to utilize infrared remotecontrol technology with such things as a DMX protocol to allow remotecontrol of on-off of a light engine. It could also be used to changebetween states. One example is steady state on for all LEDs so that itfunctions as a constant on porch light for example, but then switch tothe timing for simulated flame to simulate a gaslight.

As can be appreciated, a light engine such as FIGS. 1A-D could beretrofit into many if not all existing types of threaded sockets. Thiscould allow the light engine to be retrofitted into any of a variety ofexisting fixtures and work off of normal household current.

On the other hand, any of the light engines could simply have eitherconnection points for an electrical cord to be plugged in to provideelectrical power. Alternatively, the light engine could have its ownpower cord with terminal plug. Still further, the light engine could behardwired and permanently connected to the power grid by wiring. Stillfurther, one optional embodiment would have either on board orconnection to a battery source. Examples would be AA batteries, 18Vrechargeable, or even solar rechargeable by including a connection to asolar photovoltaic panel or panels.

As can be further appreciated, by appropriate manufacturing techniques,the light engine can be ruggedized. For example, it could be made ofmaterials that are sealable against at least fluids and have appropriatepower connection such that the light engine could be placed underwater.This could give aesthetic effect to such things as swimming pools,artificial or real ponds, fountains, or other underwater applications.The materials and their assembly could also be ruggedized in the senseof being sealed against environmental conditions such as rain, sleet,snow, dirt, dust, and debris. The materials could also be selected tohave good lifespan relative to environmental conditions such as theextremes of outdoor temperature, humidity, wind, and the like.

As will be appreciated, and as shown by the non-limiting examples in thefigures, the form factor for the light engine and/or shroud can vary.Another example would be in the form of recessed lights, in the form ofsimulated torches on poles, or almost any other form factor. This wouldinclude customized form factors according to need or desire.

a) Other

As will be appreciated by those skilled in the art, other changes ormodifications are possible to implement the invention. Variationsobvious to those skilled in the art will be included within theinvention, which is defined by the following claims.

What is claimed is:
 1. A light engine comprising: a. a three-dimensionalsubstrate having a top and a bottom; b. a set of LEDs spaced apart fromone another on the substrate from at or towards the bottom to at ortowards the top of the substrate in three dimensions; c. a powerinterface adapted for connection to an electrical power source; d. acontrol circuit between the power interface and the LEDs.
 2. The lightengine of claim 2 wherein the substrate is: a. opaque; b. diffusivelyreflective; or c. translucent.
 3. The light engine of claim 3 whereinthe control circuit is programmed to simulate a flame, wherein thecontrol circuit: a. drives selected LEDs towards the bottom to quicklyturn on or off and/or change intensity; b. drives selected LEDs towardthe middle to periodically turn on and off in groups that move fromtowards the bottom to towards the top; c. drives selected LEDs towardsto top to periodically turn on and off.
 4. The light engine of claim 3wherein the control circuit is programmed for one or more of: a. to turnthe LEDs on and off according to the timing chart of FIGS. 13A and B andTable 1; b. to turn the LEDs on and off according to the sequence ofFIGS. 22A-DD; c. to dim some or all of the LEDs by a manual or remotecontrol; or d. selectively turn on all the LEDs to steady state on by amanual or remote control.
 5. The light engine of claim 1 wherein thesubstrate comprises: a. a flexible material formed into thethree-dimensional shape; or b. multiple sections formed into thethree-dimensional shape.
 6. The light engine of claim 1 wherein thepower interface comprises an electrical cord or a threaded base for anelectrical socket.
 7. The light engine of claim 1 wherein the powerinterface comprises a an electrical connection to: a. an on-board orexternal battery; or b. a solar power source.
 8. The light engine ofclaim 1 in combination with a fireplace and the substrate is elongatedin a horizontal direction.
 9. The light engine of claim 8 wherein theelongated shape is triangular in cross-section and the LEDs aredistributed at least on opposite sides of the elongated shape, furthercomprising the elongated shape is transparent or translucent.
 10. Thelight engine of claim 1 further comprising: a. one or more additionalsets of LEDs on the substrate, each with its own said control circuit,the additional sets of LEDs spaced from the said set of LEDs and/orconfigured to be controlled in a different sequence than the said set ofLEDs, wherein the LEDs of each set have the same or differing operatingcharacteristics comprising one or more of color temperature, intensity,or output distribution, or b. one or more additional substrates eitheradjacent to or nested within the said substrate, each of the one or moreadditional substrates having an additional set of LEDs, each with itsown said control circuit, each the additional set of LEDs spaced fromthe said set of LEDs and/or configured to be controlled in a differentsequence than the said set of LEDs, wherein the LEDs of each set havethe same or differing operating characteristics comprising one or moreof color temperature, intensity, or output distribution.
 11. The lightengine of claim 10 wherein the generally three dimensional shapecomprises at least one of: a. a cylinder; b. a frustum; c. a truncatedcone; d. star-shaped in cross-section; e. domed-shape; and f. a domeshape with star-shaped cross section.
 12. The light engine of claim 10further comprising a shroud over the LEDs, the shroud comprising: a.transparent material; b. translucent material; c. at least partiallylight transmissive material; or d. light diffusing material.
 13. Thelight engine of claim 11 wherein the rotated shape comprises a bulbshape wherein: a. the substrate is generally a cylinder; b. the shroudis generally a cylinder concentric to the substrate; c. and furthercomprising: i. a cap over first adjacent ends of the substrate andshroud; ii. a cap over second adjacent ends of the substrate and shroud;iii. the power interface comprises a threaded base adapted forthreadable mounting in a threaded light socket.
 14. The light engine ofclaim 13 in combination with a lighting fixture, the lighting fixtureincluding a shroud over the LEDs, the shroud comprising: a. transparentmaterial; b. translucent material comprising one of hammered glass, sandblasted glass, or etched glass; c. at least partially light transmissivematerial; or d. light diffusing material comprising microfacetedmaterial, or material that scatters light by one or more of refraction,diffusion, or total internal reflection.
 15. A method of simulating aflame comprising: a. positioning an array of LEDs in three dimensionalspace; b. controlling on and off sequence and timing of the LEDssequence to simulate the appearance of a jumping flame to observers by:i. periodically varying intensity and/or on/off status of LEDs lower inthe array, and ii. periodically varying on/off status of LEDs higher inthe array differently than lower in the array.
 16. The method of claim15 wherein the array is: a. on at least two opposite sides of an axis;or b. substantially 360 degrees around an axis.
 17. The method of claim15 wherein the array is: a. generally cylindrical around an axis; or b.a multiplane, multi-faceted polyhedron shape around an axis.
 18. Themethod of claim 15 wherein array is mounted on a flexible circuit board.19. The method of claim 18 wherein the flexible circuit board is: a.transparent; b. at least partially light transmissive; or c.translucent.
 20. The method of claim 15 further comprising a coveringover the LEDs comprising a shade or shroud which is: a. transparent; b.at least partially light transmissive; c. translucent.
 21. The method ofclaim 15 wherein the controlling comprises: a. a repeating regimen of i.sequentially on and off LEDs beginning at or near one end of the axisand proceeding towards an opposite end of the axis.
 22. The method ofclaim 21 wherein the controlling comprises varying: a. which LEDs areturned on and what times; b. brightness of the turned-on LEDs; c. speedof the regimen; d. how far towards the opposite end the LEDs are turnedon; e. duty cycle of electrical power to the LEDs by pulse widthmodulation.
 23. The method of claim 15 wherein the array is; a.relatively uniformly populated around the three dimensional shape fromone end along the axis to an opposite end, and b. more sparselypopulated at the opposite end.
 24. The method of claim 15 furthercomprising remotely controlling the starting of the regime.
 25. Themethod of claim 15 further comprising remotely adjusting the regime. 26.The method of claim 15 wherein the LEDs are of a certain: a. colortemperature; b. size; c. power; or d. variations of any of theforegoing.
 27. The method of claim 15 wherein the array is packaged in ahousing including a threaded base that is mateable with a threadedelectrical socket.
 28. The method of claim 15 wherein the array ispackaged in a housing that is self-standing.
 29. The method of claim 15wherein the array is packaged on a form that can be placed in afireplace.
 30. A method of simulating a flame comprising: a. controllingon/off, sequence, brightness, and timing of individual LEDs or sub-setsof LEDs of a three dimensional array of LEDs through an optical mediumto create of the appearance of traveling lights from bottom to top ofthe array.
 31. The method of claim 30 wherein the optical medium is atranslucent material.
 32. The method of claim 31 wherein thethree-dimension array comprises: a. LEDs on a flexible circuit board.33. A simulated flame light comprising: a. a light transmissive cylinderwith opposite open ends; b. a threaded base adapted for mating insertioninto a threaded electrical socket mounted at one of the opposite openends of the cylinder; c. a top cap mounted to the other of the oppositeopen ends; d. a flexible circuit board cylinder with opposite open endsmounted co-axially with and inside the translucent cylinder andincluding an array of LEDs; e. a transformer mounted inside thetranslucent cylinder electrically connected to the threaded base; f. acontrol circuit mounted inside the translucent cylinder electricallyconnected to the transformer and the LEDs, the control circuit includingdrivers to control on/off and intensity of the LEDs over time ofoperation.